### New CBSE Sample Paper 2021 class 11 Physics

Annual Examination

Class-XI

Subject- Physics

Time: 3 hour/M.M.-70

All questions are compulsory.

- Section A contains 5 questions of 1 mark each.
- Section B contains 5 questions of 2 marks each.
- Section C contains 12 questions of 3 marks each.
- Section D contains 1 value based question of 4 marks.
- Section E contains 3 questions of 5 marks each.

**Section-A**

1- What is the angular velocity of the hour hand of a clock?

2- A bucket containing water is rotated in a vertical circle. Explain why water does not fall.

3- Name the largest and smallest practical unit of energy?

4- Explain why small drops of Mercury are spherical and large drops become flat?

5- Can we increase the temperature of a gas without supplying heat to it?

**Section-B**

6- Briefly discuss the limitations of first law of thermodynamics.

7- Explain-

i) Boyle’s law

ii) Charle’s law

Why are they not applicable to real gases in all states?

8- Explain what is meant by specific heat of a substance. What are its units? How is molar specific heat different from specific heat?

9- A flywheel rotating at a speed of 600 rpm about its axis is brought to rest by applying a constant torque for 10 seconds. Find the angular deceleration and angular velocity 5 second after the application of the torque.

10- State and explain work energy principle.

**Section-C**

11- Convert energy of one joule into ergs.

12- A stone tied at the end of string is whirled in a circle. If the string breaks, the stone flies away tangentially. Why?

13- State and prove the principle of conservation of linear momentum.

14- State and establish principle of conservation of energy.

15- State and prove theorem of parallel and perpendicular axes.

16- Discuss the variation of g with height and depth.

17- State and prove Hook’s law.

18- State and prove Pascal’s Law.Give one application of it.

19- Discuss work done in an adiabatic process.

20- What do you understand by zeroth and first law of thermodynamics?

21- Find an expression for the pressure exerted by a gas.

22- Derive an expression for moment of inertia of a thin circular ring about an axis passing through its centre.

**Section-D**

23- Ram noticed a big granite rock in his locality. He thought that if they worked upon it they could earn money. He broke the rock using a bomb. The rock was made into slices. They established a granite industry. Many of the people in the surroundings started to earn and live comfortably.

i) What values of Ram impress you?

ii) A bomb is thrown in a horizontal direction with a velocity of 50 m/s. It explodes into two parts of masses 6 kg and 3 kg. The heavier fragment continues to move in the horizontal direction with velocity of 80 m/s. Calculate the velocity of the lighter fragment.

**Section-E**

24- State and prove Bernoulli’s theorem also write two applications of it.

25- Describe Carnot engine in detail and derive an expression for efficiency of this heat engine.

26- State and Derive expression for orbital speed, Time period, height of satellite and binding energy of satellite.